The rapid technological advancement of functional Magnetic Resonance Imaging (fMRI) in recent decades has greatly deepened our understanding of the brain and the multitude of processes taking place within it at all times. We’ve gained insight into the neural mechanisms behind attention, consciousness, and perception, but as a recent study by researchers at the University of Western Ontario demonstrates, fMRI can also be used to understand a more unexpected and understudied topic: humour!
Using the iconic television series Seinfeld, as well as a series of audio recordings of jokes and non-jokes, the research team scanned the brains of 26 participants to identify the brain regions most involved in humour comprehension and humour appreciation, respectively.
What’s the deal with the brain’s comprehension of humour?
As outlined above, the researchers highlighted two distinct aspects of humour. The first, comprehension, is essentially how much we “get” the joke. How much do we recognize the absurdity or punchline for what it is? The second, appreciation, is more subjective and relates to how much we enjoy the joke. How long or hard do we laugh? With this distinction in mind, the researchers were interested in understanding which brain regions were involved with each aspect of humour.
Two candidates that were hypothesized to be involved were the dorsal striatum (DS) and ventral striatum (VS). The DS, which previous research cited by the authors has shown to be involved in resolving ambiguity, suppressing prepotent responses, working memory, and shifting attention, was hypothesized to be involved in humour comprehension. In contrast, the VS was hypothesized to be involved in humour appreciation.
S2E13: The fMRI
The researchers recruited 26 adult participants who completed two tasks for the study: an auditory joke task and a Seinfeld viewing task. For the first task, participants listened to 80 audio clips — 40 jokes and 40 non-jokes — while their brain activity was measured via fMRI. After listening to each clip, participants then indicated whether they thought the audio was a joke or not (comprehension), and how funny they found it on a scale from one to four (appreciation).
The second, arguably more fun, task required the participants to watch a full episode of Seinfeld while their brain activity was recorded in an fMRI machine. After that, they were asked to indicate how familiar they already were with Seinfeld, how often they watched sitcoms, how funny they found the episode they watched, as well as some comprehension questions to ensure they had actually paid attention to the episode.
To interpret whether brain activity occurred during humour comprehension or appreciation, the researchers classified humour comprehension as occurring during the two seconds before the laugh track after a joke, while humour appreciation was said to occur in the middle two seconds of the laugh track.
What’s the punchline?
The researchers found that in the audio task, there actually was no significant difference in the participants’ ability to classify the clips as a joke or non-joke (although jokes were correctly identified at a slightly higher rate than non-jokes). Not surprisingly though, there was a significant difference in funniness ratings between jokes and non-jokes, with jokes being rated higher.
For the Seinfeld viewing task, the researchers found that both the DS and VS were active during humour comprehension, while only the VS was active during humour appreciation. In both tasks, other brain areas that were activated for humour comprehension included the inferior frontal gyrus, middle frontal gyrus, supplementary motor area, middle temporal gyrus, temporal poles, and midbrain. For humour appreciation, the temporal cortex was activated.
In a press release, one of the study’s lead authors, Margaret Prenger, also outlined the implications of the findings for patients with Parkinson’s disease, whose altered dopaminergic pathways may affect their humour comprehension and appreciation.
